1. Field of the Invention
The present invention relates to animal training systems, and, more particularly, to a method and apparatus for adjusting the correction level or range of correction levels of an animal training receiver.
2. Description of the Related Art
Stimulus collars for animal training, particularly dog training, are known which can provide a variety of stimuli to the animal to encourage a trained response by the animal, and/or to discourage an inappropriate response. Such stimuli can include electrical, sound and vibrational stimuli, for example. In the case of an electrical stimulus, a collar worn receiver typically includes a pair of electrodes which can deliver the electrical stimulus to a dog's neck. The receiver energizes the electrodes responsive to a transmitter. Examples of such a transmitter can include a remote training transmitter hand operated by a human trainer, a containment transmitter and an avoidance transmitter. For a bark control collar, a collar worn receiver may receive audio or vibration signals from a microphone or transducer attached or connected to the receiver unit or the collar.
When activated by an appropriate signal from a corresponding transmitter or transducer, electrical stimulation is provided to a dog, for example, through the collar worn receiver electrodes which are in contact with some part of the dog's neck. In order to accommodate differences between breeds, individual dog temperament, training conditions, etc., it is advantageous to provide a wide range of possible stimulation, which range is selectable at the transmitter by the trainer. For example, the general difference in coat/skin of one breed versus another breed may provide a general difference in contact resistance, which can generally make a given breed more correctable at a lower electrical stimulation than another breed which has a thicker coat with a downy underlayer, for example. Further, a relatively strong willed dog may require more stimulation for a given training condition than a more amenable dog. Although the proper use of such electronic collars is a very effective, efficient, and humane way to train or control dogs (or other animals such as monkeys and horses) for a variety of purposes, such as general obedience, performance trials, hunting, herding, and police work, to be most effective and humane, it is important that electronic stimulus collars are able to reliably and consistently apply the intended degree of stimulus to the skins of a wide variety of dogs under a wide variety of conditions.
For example, training conditions can play a large role in determining the amount of stimulation necessary for a given dog. Skin and fur conditions can range from very dry and nearly electrically nonconductive to very wet and highly conductive. The fur of a dog running through wet cover conditions or jumping into a pond or creek, for example, during retrieval training or bird hunting, may be nearly electrically nonconductive during the early part of a training procedure or hunt and very wet and conductive during a later part thereof. Consequently, a low shock level in such a situation may be transformed, because of the skin and fur conditions brought on by the training circumstance, to a relatively high and perhaps unacceptable or inappropriate stimulus level.
Failure to deliver an appropriate stimulus at precisely the correct time in a dog training situation can result in a confused, poorly trained animal, and may also reverse previous training accomplishments. Consequently, the reliability of providing an intended electrical stimulus level to the skin of the dog under a wide variety of conditions (eg., of collar tightness, thickness and wetness of fur, general sensitivity of the particular dog to electrical stimulus, and the presence of distracting influences or occurrences) is quite critical to the overall effectiveness of electronic stimulus collars and the associated training techniques.
The receivers of modern electronic collars quite often can be programmed to deliver one of several levels of stimulation for a given collar receiver input, or in the case of remote training systems, one of several levels of stimulation may be selectable by the human trainer using pushbuttons, or other command input devices. For a particular dog on which an electronic stimulus collar is being used for the first time, the lowest level stimulation signal may be applied to the neck of the dog. If the dog does not appear to have noticed the stimulation (for example, the dog does not change head position or ear posture, cock its head, or exhibit an involuntary muscle twitch), a higher stimulation level can be selected until a threshold stimulus level is established for that dog, as evidenced by one of the above reactions. Stimulus intensity thereafter is varied in noticeable increments by depressing the various intensity controls on the remote transmitter or by reprogramming the receiver collar as required by the particular training circumstance. However, such electronic collars are limited to a discrete number of stimulation levels which, given a particular dog, training objective and training conditions, may not provide an adequate selectable range of stimulation.
The electrodes of an electronic collar are typically connected to the secondary winding of a transformer within the collar's receiver, and the electrodes and the animal's contact resistance between the electrodes represents a load to the transformer. When the primary winding of the transformer is appropriately energized, the secondary winding provides an electrical stimulation to the load, i.e., the animal. A greater electrical load resistance effectively reduces the electrical stimulation, so that one way of changing stimulation levels is to change the load resistance, as opposed to changing the characteristics of the electrical energy provided to the primary winding.
A resistive electrode structure for an electronic stimulus collar is known which includes a base attached to a connecting element of the electronic stimulus collar. An electrode of the resistive electrode structure includes a tip adapted to supply electrical stimulus to the skin of an animal. A resistive material is electrically connected between a conductor for electrical connection to an output of the electronic stimulus collar and the electrode. This resistance effectively increases the load resistance presented to the secondary winding and accordingly modifies the stimulation level delivered to the animal for a given electrical input to the transformer primary winding. Various such resistive electrode structures which have various resistances can be interchangeably connected to the electronic stimulus collar to vary the level of stimulus applied to the skin of the animal. Therefore, if the electronic stimulus collar inherently has three selectable or programmable stimulation levels, and if there are five different resistive electrode structures available each with a different electrical resistance, the number of electrical stimulation levels has now increased from three to fifteen (three times five), for example.
Problems with such a resistive electrode structures are that the electrodes are relatively difficult and expensive to manufacture, and can be unreliable. Another problem with these resistive electrode structures is that they can be difficult to distinguish from a non-resistive electrode since the resistor is embedded within the electrode. Another problem with these resistive electrode structures is that electrodes in general can be provided in different lengths to accommodate for different fur thicknesses, which multiplies the number of resistive electrodes required. Yet another problem is that a damaged resistor within the electrode, such as an electrical short or open, is not readily apparent, which increases the risk of an inappropriate correction level.
What is needed in the art is a way of increasing the resistance between an electronic collar's output terminals, which does not embed resistive elements into the electrodes.